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Thursday, February 20, 2014

Boundaries for the Next Discovery Mission Selection

In my post a
couple of weeks ago on the selection of NASA’s next low cost planetary
mission, I said that the conditions NASA imposed on scientists proposing
missions would determine much of what kind of missions scientists could impose.

NASA will accept proposals to study any solar system body except the sun and the Earth. Scientists cannot propose missions to study planetary systems around other stars (NASA astrophysics program funds these missions.)

NASA announced that the budget for the spacecraft, instruments, and
data analysis (the Principal Investigator (PI) budget) would be $450M (FY15
dollars). This is a small increase from
the last competition’s PI budget of $425M, and by itself would not keep up with
inflation.

Outside of the PI’s budget, NASA will pay for the cost of the mission
launch. For the first time, NASA will
pay for the cost of the mission’s operation outside of the PI budget. In past competitions, missions with long
flight times, and hence high operations costs, were at a disadvantage to
missions with low operations costs. This
appears to be an effort to equalize operations costs. Missions that would benefit are any with
flight times of several years compared to the weeks or months to reach Venus,
the moon, or Mars. With operations costs
not counted against the PI’s budget, the new competition probably keeps up with
inflation compared to the previous competition.
(NASA’s announcement does emphasize that the operations costs projected
for a mission must be ‘reasonable’.)

The major limitation for this competition is that NASA will not provide
a radioisotope power system for this competition. While recent NASA presentations suggests it
has sufficient plutonium-238 fuel to support a Discovery mission, that fuel
could not be prepared in time to meet the expect launch date for this
competition. As a result, any mission
that cannot use solar power is effectively eliminated. This would include missions beyond Jupiter,
to the permanently shadowed lunar polar craters, or where large solar panels
just won’t work like for a mission that would make multiple landings on a comet
(see this description
of the CHOPPER mission proposed for the last competition).

NASA traditionally offers scientists various technologies at the space
agency’s cost that it would like to see tested in space. For this competition, NASA says it is
considering providing a version of the NASA Evolutionary Xenon Thruster (NEXT)
ion propulsion engine as well as heat shield technology for missions that would
send a probe into planetary atmosphere.
These former would benefit missions that would require large amounts of
thrust such as main belt asteroid missions or comet rendezvous missions. The latter would benefit missions such as
Venus atmospheric probes.

NASA also is considering requiring proposals to include carrying its
Deep Space Laser Communications (DSLO) package.
This technology was tested on the LADEE mission currently orbiting the
moon and showed that lasers could return much larger volumes of data than
traditional radio systems. NASA would
now like to try this technology from a spacecraft in deep space. Missions with low data rates such as Venus
atmospheric probes probably would see little benefit from the DSLO system. Missions with lots of imaging data such as Venus
radar mappers or Io multi-flyby missions would make good use of the DSLO
system.

One other new requirement is a limitation on how much of the cost of
instruments foreign space agencies can contribute. NASA has had a limitation that foreign
governments could not contribute more than one-third the cost of the total
mission. That cap now also applies to
the contribution to the cost of the science payload, too. This appears to be a way of preventing a
proposal team from minimizing its PI costs by filling most of the payload with
instruments paid for by other governments.
NASA apparently wants US planetary missions to provide opportunities for
US scientists to fly their instruments.

All in all, this looks to be a nice opportunity that keeps the
Discovery program on track to continue to support innovative missions to a
variety of destinations in the solar system.

Key dates (subject to change)

May 2014 – release of draft Announcement of Opportunity with details
for proposers

4 comments:

In considering the cost cap, it's important to keep in mind that $425M in FY10 dollars is $470M in FY15 dollars (according to the NASA New Start Inflation Index). So the $450M (FY15) cost cap sort of assumes a Phase E cost of at least $20M (FY15). Missions with Phase E's exceeding $20M are, therefore, not discouraged.

Anon 2 - No Titan this time, but two hopeful tidbits. First, NASA plans to offer an MMRTG plutonium power source for all subsequent Discovery competitions (so the lack of one this time is just bad timing in terms of ramping up production). Also, the latest budget proposal shows the Discovery program ramping up to have a budget that would allow a selection every two years by the end of this decade.

About Me

You can contact me at futureplanets1@gmail.com with any questions or comments.
I have followed planetary exploration since I opened my newspaper in 1976 and saw the first photo from the surface of Mars. The challenges of conceiving and designing planetary missions has always fascinated me. I don't have any formal tie to NASA or planetary exploration (although I use data from NASA's Earth science missions in my professional work as an ecologist).
Corrections and additions always welcome.